Union dyeing

Halb-weiss, n. Textiles) half-bleach, -wert-druck, m. half-value pressure, -wertsbreite, /. width at half of maximum intensity (of a spectral line or band), -wertzeit,/. half-life period. -woUe, /. half-wool, union. -woU-farberei, /. union dyeing, -wuste, /, semi-desert. 

One-bath scour and dye system for union dyeing nylon/spandex blends. System consists of ... 

The advent of regenerated and synthetic man-made fibres has greatly increased the scope for making blends of two or more components. The oldest mixture of all is wool and cotton, which is used to ma e cloths known as unions. For this reason dyeing of mixtures of these two fibres is often referred to as union dyeing. There are three possible ways of dyeing mixtures of protein and cellulosic fibres ... 

There are a great number of union dyes available which are usually mixtures of neutral dyeing acid, and direct dyes, giving solid shades with careful manipulation of temperature and use of assistants. It is usually found that the cellulosic fibre dyes to a full shade at 60° to 70°C (140° to 158°F), and as the temperature approaches the boil an increasing amount of the dye is taken up by the protein fibre. At the boil some of the colour adsorbed by the cotton will be transferred to the wool so that, in time, the latter will become much heavier in shade. It is apparent, therefore, that a good solid result depends to a great measure upon control of temperature. It is usually necessary to add 5 to 20 per cent of common salt to promote exhaustfon of the direct dye on the cellulose, and with heavy shades as much as 40 per cent may be necessary. 

Cardamone, M.J., Maimer, W.N., Blanchard, J., Lambert, A.H., Brady, J.B., 1996. Pretreatment of wool/cotton for union dyeing, part 1 resins plus choline chloride. Text Chem. Color. 28,19-23. 

Cardamone, J.M. Manner, W.N. Phillips, J.G. In Book of Papers, 1997 International Conference and Exhibition, Effective Biguanide Pretreatments for Union Dyeing Wool/Cotton Blends, American Association of Textile Chemists and Colorists North Carolina, 1997, pp. 388-399. 

Nitro Powder Company Aetna Explosives Company Bartlett Howard Company Federal/Union Dye Chemical TOTAL... 

Union Dye and Chemical Company (Federal Dyestuff Chemical Corporation), 62-64... 

Features Very stable suitable for union dyeing of mixed fabrics effective in acid, alkaline and salt solutions... 

Phloroglucinol is Hsted in the Colourindex as Cl Developer 19. It is particularly valuable in the dyeing of acetate fiber but also has been used as a coupler for azoic colors in viscose, Odon, cotton (qv), rayon, or nylon fibers, or in union fabrics containing these fibers (157). For example, cellulose acetate fabric is treated with an aromatic amine such as (9-dianisidine or a disperse dye such as A-hydroxyphenylazo-2-naphthylamine and the amine diazotizes on the fiber the fabric is then rinsed, freed of excess nitrite, and the azo color is developed in a phloroglucinol bath at pH 5—7. Depending on the diazo precursor used, intense blue to jet-black shades can be obtained with excellent light-, bleach-, and mbfastness. 

A. I. Solodukhin, Proipv. Isol i Uitaminov, Antihiotikov Biol Aktivn. Ueshchestv, 145—181 (1965). Production and Use of Food Dyes. A review of the synthetic and natural food dyes used in the Soviet Union. 

There is as yet no agreed international list of permitted food colours. Thus a food dye that is permitted in one country may be considered unacceptable in another. The synthetic food colorants permitted in the European Union are listed in Table 1.8 [60]. All were originally introduced as acid dyes for wool many years ago. Furthermore, more than thirty colorants of natural origin are permitted in most countries. The natural carotenoid dyes are of outstanding importance for colouring edible fats and oils. These yellow to red methine dye structures occur in many families of plants and animals, including vegetables, berries,... 

It is otherwise with cotton, which is almost chemically pure cellulose, and hence is chemically indifferent in a tinctorial sense. Here combination with the dye results from the use of mordants which are adsorbed colloidally on the fibre before dyeing. The mordant can then enter into chemical union with the dye as a complex compound. For an important group of acid dyes (p. 335) the mordants are chiefly metallic hydroxides, namely, those of chromium, aluminium, iron, antimony, tin, etc., whilst for basic dyes tannin is the usual mordant. 

At this point the oxidation stage of quinonediimine has been fully reached its (very unstable) salts have scarcely any colour. The production of colour only takes place when quinonoid and benzenoid systems are present together. The molecular union of the two substances at different stages of oxidation produces the intense absorption which is a prerequisite for the formation of a dye (Willstatter and Piccard). This union need not take place in the proportion 1 1, which obtains in the present case. The relations between quinhydrone and quinone-quinol are quite similar (p. 314). 

The technical preparation of crystal violet and of its methyl-free parent substance, parafuchsine, almost the oldest of the triphenylmethane dyes, is not so easily explained. As is well known, in this process aniline and p-toluidine are united by oxidation in an acid melt. (In the preparation of fuchsine itself, which contains a methyl group attached to one of the benzene rings, o-toluidine is an additional ingredient.) Although all the phases of this important synthesis have not yet been experimentally established, we may nevertheless explain it on the basis of a dehydrogenation similar to that involved in the formation of malachite green. Moreover, the union of several molecules of base proceeds exactly according to the principle on which indamines are formed (p. 321) (Bucherer). 

Fig. 9.2 Patterns of vertical water flow in a porous medium, as a function of the initial water content. Shown here are two patterns of water infiltration, in two different dry and wet soils, following infiltration of 40 mm of water containing Brilliant Blue FCF as a dye applied to the ground surface (Flury et al., 1994). Reproduced by permission of American Geophysical Union. Flury M, Fluhler H, Jury W, Leuenberger J (1994) Susceptibility of soils to preferential flow of water A field study. Water Resour Res 30 1945-1954, doi 10.1029/94WR00871. Copyright 1994 American Geophysical Union...

We will briefly trace the evolution of chemicals production through three of the largest U.S. chemical companies and the German cartel. We will see that each of these companies can be basically defined through a single chemical DuPont by HNO3, Union Carbide by acetylene, Dow Chemical by CI2, and BASF by the dye industry. 

Zeno W. Wicks, Jr., Consultant, Las Cruces, NM, Drying Oils Pieter R, Wiederhold. General Eastern Instruments Corporation. Water-town. MA, Hygrometry and Psychrometry Paul Wight, Seneca Specialties. Manchester, U.K. Xanthene Dyes E. Williams, Cobalt Information Centre, Londtm. UK, Cobait Richard A Wilsak, Amoco Chemical Company. Naperville. IL Butylenes Richard A. Wilson, International Flavors Fragrances. Union Beach, NJ. http //www.ifT.coni/. Benzyl Alcohol and /j-Phenethyl Alcohol Oils, Essential... 

Although 10 only possesses average fastness properties, it enjoys great importance and, because of its good leveling power, is used for dyeing union fabrics, polyamide, and chrome leather. 

Dyes based on these compounds possess, in addition to good lightfastness, excellent wetfastness and are usually neutral-dyeing on wool. This, although of no importance for dyeing pure wool, plays an important role in dyeing blended spun yam and blended fabrics of wool and cotton or wool and viscose staple. The neutral-dyeing acid dye can be used in combination with direct dyes (union wool recipes). Examples are C.I. Acid Yellow 56, 24825 [6548-24-9] (17), and C.I. Acid Red 154, 24800 [6507-79-5] (18 R = CH3). 

European Union. In the EU colorants which may be used in foodstuff are regulated in 94/36/EC On Colours for Use in Foodstuff. (Table 5.5). Food additives listed in EEC Directives are assigned E numbers. Approved dyes within the EU are also defined as food additives and thus carry E numbers. A substance with an E code and number is valid throughout the EU (E = EEC number of food additives). 

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